Method of thermochemically cutting metal bodies



J. H. BUCKNAM ETAL 2,510,210

METHOD oF TEEEMOCHEMTCALLY CUTTING METAL BODIES June 6, 1950 3 Sheets-Sheet 1 Filed May 26, 1944 ATWT@ INVEN o S JAMES H. @Lc/VAM RQGER s. BAECOCK ATTORNEY June 6, 1950 J. H. BucKNAM :TAL l2,510,210

METHOD l0F THERMOCHEMICALLY CUTTING METAL BODIES A 3 Sheets-Sheet 2 Filed May 26, 1944 INVENTORS JAMES H. BUC/(NAM ROGER 5. BABCOCK E ATTORNEY June 6, 1950 J. H. BUCKNAM ETAL 2,510,210

METHOD OF THERMOCHEMICALLY CUTTING METAL BODIES 3 Sheets-Sheet 3 Filed May 726, 1944 INVENTORS JAMES H. BUC/(NAM my' 3 LJ] ROGER s BABcoc/r BY i ATTORNEY -ing production cycle.

severing by the customary thermochemical `methods in the past has not been suiiicient comlline invention; j

Patented June 6, 1950 METHOD OF THERMOCHEMICALLY CUTTING BIETAL BODIES d Roger S. Babcock, Cran- J ames H. Bucknam an ford, N. J., assignors to The Linde Air Products Company, a corporation of Ohio Application May 26, 1944, Serial No. 537,400

3 Claims.

vpipe is stationary and itis unnecessary closely to correlate the severing operation with an exist- However, vthe speed of pared with the speed of mechanically shearing hot steel slabs and plates in course of manufacture, to avoid delaying or interfering with the production of the steel shapes inthe rolling mill.

Accordingly, a principal object of the present invention is to provide a method of thermovchemically cutting metal bodies which is rapid, `efcient, adapted to cut a slot of minimum width,

and which is especially advantageous for use in successively rapidly severing hot metal bodies such as steel slabs and plates, in process of manufacture in a rolling mill, without delaying or interrupting the production of such bodies.

Other objects of the invention are to provide an 'improved method of cutting an elongated metal body by propelling a row of thermochemical cutting jets simultaneously along a cutting line extending across the body; an improved thermochemical cutting method which eficiently utilizes the heating and cutting gases; and a novel kmethod of piercing and cutting relatively thick Work with oxygen.

The manner in which these and other objects are attained by the invention-will be apparent -from the following description having reference to the accompanying drawings, in which:

Fig. l is a perspective view partially in section showing one method of carrying out the invention;

Fig. 2 is a sectional view taken, on line 2-2 of Fig. 1;

Fig. 3 is a sectional view exemplifying a method of the invention;

Fig. 4 is a longitudinal sectional view of a nozvzle taken on line 4-4 of Fig. 5;

Fig. 5 is a view partly in cross-section taken on the line 5 5 of Fig. 4.;

Fig. 6 is a plan view of apparatus exemplifying Fig. 7 is a view in elevation of the apparatus shown in Fig. 6; and

Fig. 8 is an enlarged view partly in section taken on line 8-8 of Fig. 6. y

According to this invention, in thermochemically severing a steel slab or plate I0, a row oi Oxy-fuel gas cutting nozzles N is positioned above the plate and along the line of cut, the preheating gases are turned on and ignited to provide a row of novel post-mixed preheating flames F; and a small area on the plate directly under each nozzle is melted and thus preheated to the ignition temperature. A jet J of oxygenis then discharged by each nozzle against the molten metal in the preheated area below the nozzle and severing is accomplished by advancing the row of nozzles, with their preheating flames and oxygen jets through a single stroke of a suicient length along a line through the preheated areas to remove the metal sections between said areas.

Further, according to the invention a method is provided which comprises preheating a metal body with a post-mixed Oxy-fuel gas ame until a molten puddle is formed. Then, increasing the velocity of the oxygen component of such flame and moving the flame laterally with respect to the body to pierce the latter While the ame is moving in one direction and finally to cut a kerf in the Work.

Referring to Fig. 1, the jets J o1 oxygen delivered by the nozzles N against the preheated areas, produce a row of holes -H through the plate I0. After thus completely piercing the plate, the entire row of nozzles depending from a boom is moved as a unit in the direction of the arrow A along a line extending through the centers of the pierced holes l-I until the cut or kerf K made by the cutting oxygen jet of the leading nozzle reaches one lateral edge of the plate and the cut or kerf K made by the cutting oxygen jet of each of the other nozzles intersects the hole made by the oxygen jet of the next preceding ,nozzle in the row. This quickly completes the ment is not essential if the 'preheating llames while being propelled are capable of heating the work to the ignition temperature, it is nevertheless desirable for purposes of conserving cutting gas during the piercing operation because gases not directed against the work are wasted.

Before the plate is completely pierced, during the interval that the row of nozzles is held stationary, products resulting from the reaction of the oxygen jets with the work leave the partially pierced holes H in a stream surrounding the jets and exert an eroding action upon the walls of the holes so pierced exceptfor the vhole cut by the trailing nozzle. After the holes are pierced completely through the plate, the .products of the thermochemical action pass vthrough the plate so that the contours of the walls of the holes have the shape shown in Figs. 1 and 2. Because the reaction products are displaced to the rear as the row of nozzles is moved forward, exerting no eroding action on the walls of the plate, the kerf between the holes is narrower 4than the diameter of the holes as is shown in Figs. 1 and 2 to a greatly exaggerated degree. `Such severing procedure is particularly advantageous in cropping lor'lin cutting into `sections a Vnot steel slab Aor plate immediately Yafter it has been ydischarged from a rolling mill and while 4it still is lsubstantially kata hot rolling temperature. Thus, Ethe severingoperation'is performed Aso rapidly that there is substantially no Vinterference "with the usual rolling mill operating time cycle.

-lTofreduce the severing time still further and to prevent jgouging vby `decreasing `the diameter of the holes during piercing, according to the invention, Yinstead of delaying the movement of 'the row of nozzles until `a row of -holes has been `pierced'completelyethrough theplate, it is preferable in some operations simultaneously to turn on the lseveral cutting Ioxygen jets and to start movingthe cutting nozzles 'alongithe cutting line 4just 'as `soon "as the several areas yon the plate surface directly under the nozzles 4have been fused 'or preheated to the 4ignition temperature mwith oxygen. Referring 'to 3, Vthe piercing operation thus Lis initiated at the preheated areas 'and 4is completed `Veryishortly after the row of nozzles starts lto move along Ythe cutting line; thereafter, the cutting proceeds, as previously described, by moving the -row of nozzles 'a 'distance equal to the vdistance Vbetween `the points `where 'the oxygen 'jjets initially jpi'erce entirely 'through the plate. lThe reason the slots in Fig. "3 are o'f smaller diameter during piercing than is the case inFigs. A1 and 2, as mentioned above,

Ais because -the hot slag formed Vduring piercing is blown out as .shown bythe dotted 'lines in "Fig 3 at only one side of each of the moving 4gas streams instead of varound each of such lines, represent ,the starting position of the nozzles N. Because no appreciable time interval exists during which the trailing cutting nozzle is not directed against the work, the starting position of the trailing nozzle with respect to-aV lateral edge E of the Work I isof small importance so far as the conservation of cutting gas is concerned.

As can .be seen from Fig. '3 the cutK, made by the trailing cutting nozzle differs from the rolling mill time cycle.

cuts K made by the other nozzles in that the cutting jet of nozzle N cuts the plate through its entire thickness from the start of the cutting operation. The advance of the row of nozzles in this modified procedure results in a kerf of substantially uniform width and additionally provides Va useful path of :escape for the oxygen jets before they'pierce through to the 'bottom of the plate and, therefore, the spread of the cutting jets and resulting lateral gouging is inhibited.

Eitherof such :rapid severing procedures may be accomplished by mounting a row of cutting nozzles N on the boom B constructed and arranged to be positioned above and parallel to the cutting 'line on the plate I0. The cutting nozzles N on the boom are movable as a unit in a straight li-ne, and are spaced apart a suitable distance to synchronize the cutting stroke and time with the For example, if a cutting time of ten seconds is allowable, and the actual cutting rate of a single cutting oxygen 4jet is 30 linches per minute, the centers of the nozzle -should be spaced five inches apart.

Apparatus for carrying out vthe invention comprises a carriage C mounted Yon a support S and positioned transversely of vthe `slab l@ to be cut. On the carriage-*C is mounted the boom B which supports the row of the nozzles VN, the number of said nozzles -being governed by -the time alv'lowed for severing and the width of the plate.

Associated with the carriage isla mechanism M capable of propelling the carriage in the direction 'of -a line extending fthrough `the centers of the holes IH pierced by the cutting jets-and `for a distance sufficient inone stroke to remove the "metal from the spaces 'between the holes. To facilitate the operation, A`means are provided for retracting the nozzle away from the plate, for -valving 'the Vvarious iiuidsin their 'proper sequence, and for protecting the nozzles and machine parts from reflected lheator slag by air screens, baffles, ior y-water cooling.

Referring `to the drawings and particularly to Figs/6,7, land-:8, theicarriage =C is varranged trans- `versely vover the plate Il) fresting on .conveyor frollers R. At intervals along Athe length of the YRunning parallel to the `boom B are an oxygen manifold ldand an acetylene manifold l5. The downlstreamor outer end of the oxygen manifold I4 and acetylene manifold I5 are each sealed by caps I6, I6. Supplying the nozzles with the appropriate gases are oxygen tubes vII and acetylene tubes IS, each connected `to #its respective manifold. At suitably spaced intervals along the carriage are wheels I9 which are mounted on bearings 29 attached to the acetylene manifold I5.

Near the upstreamfendfofthe oxygen manifold I4 and acetylene manifold I5, a mounting plate 2I is welded or otherwise lfastened to the Vside of such manifolds opposite the nozzles N. ABraces 22 -welded to the boom "B, the oxygen manifold I4, and the acetylene manifold I5 -rigidly hold these three longitudinal members in spaced relation to one another. 'A plate '23 is welded or otherwise secured to the acetylene and voxygen manifolds on the side of -the carriage YC opposite the nozzles N tosupport counterweights -24 which counterbalance the weight of the nozzle-carrying n N may f2,515,gi

portion of the boom. The oxygen manifold 'I4 has near its inlet end a gate valve which is by-passed by a line having a globe valve 26 and is connected to an oxygen supply line 21. The acetylene manifold I5 is similarly provided with an acetylene valve 28 and is connected to an acetylene supply line 29.

Rigidly and perpendicularly secured to the mounting plate 2| is a horizontal shaft or pivot 30 as shown in Fig. 8. The pivot 30 is adapted to engage a bearing 3| mounted on the carriage support S. The support S rests on a base 32 mounted on the iioor adjacent the plate or slab conveyor. Such base may be a piece of steel plate or other material capable of supporting the apparatus and is threaded to receive bolts 33 for clamping two angles 34, 34, the latter being spaced apart transversely of the carriage C. Held by the oppositely disposed angles 34 are trurmions 35 serving as the lower support for an adjustable crank or link L. The lower end of the link L has laterally extending webs 36 which serve to-span the distance between the trunnions 35 and the adjustable link L. The Webs 36 are journalled on the trunnions 35. The adjustable link L consists of a tubular sleeve 3l within which is disposed a spindle 38 threaded at its upper end and guided at its lower end. A nut 39 engaging the spindle 38 is rotatably secured to the upper end of the sleeve 3'I by an extension 40 within a recess 4| at the upper end of the sleeve. Several holes 42 are drilled in the nut 39 to accommodate a spanner wrench for changing the length of the adjustable link by vrotating the nut. Welded or otherwise fastened to the top of the spindle 38 is a horizontal tubular member 43 having secured therein at each end the two bearings 3|, 3|. The bearings 3|, 3| carry the pivot 30 which has secured on one end a collar 44 outside of one bearing 3| and which is, at its other end,

`*Welded to the mounting plate 2|.

Both motion and support are imparted to the carriage C by an upwardly extending inclined arm 45, one end of which is secured to the sleeve `3`| and the other end to a bearing 46 of the propelling mechanism M. Journalled within the bearing 4B is a pin 41 extending Jfrom a bored block 48 and held against longitudinal movement by a nut 40. A threaded rod 50 having a handwheel 5| passes through the hole of thev block 48, which hole forms a bearing for a threadless shank portion of the rod 50. The threaded portion of the rod 50 engages threads of a threaded block y52 having a horizontally extending pin 53 which is journalled in a bearing 54, the pin being secured against longitudinal movement by a collar 55. The bearing 54 is secured to the upper end of a post P in parallel relation to the bearing 40.

-The post P in turn has a flange 56 at its lower end which is secured to the base 32 adjacent one of the angles 34.

While the cutting blowpipes and their nozzles in certain cases be of the conventional type employed for flame cutting metal, special advantages such as stability and freedom from hflashback and backre are obtained in the herein-disclosed severing method by using an improved post-mixed flame cutting nozzle, such as that shown in Figs. 4 and 5.

According to this invention, and as shown byy way of example in Figs. 4 and 5, each cutting -nozzle N is constructed to provide a cutting oxygen stream as Well as a combustible preoxygen and acetylene, as these mixing the acetylene and preheating oxygen within theblowpipe or the nozzle t prduce such preheating mixture. As shown, the nozzle N comprises a main body ||0 which has a central oxygen passage extending longitudinally therethrough, and also has a plurality of longitudinally extending acetylene passages II2 arranged in a row spaced radially from the oxygen passage |II. Therear end of the body ||0 and the inlet ends of the passages |I| and ||2 are constructed and arranged in 'a conventional manner to couple the nozzle to a suitable blowpipe head adapted to supply oxygen under pressure to the passage I and acetylene under pressure to the passages ||2. At its front end, the cross-section of the body ||0 is reduced to provide a cylindrical surface ||3 and an annular shoulder ||4, and is further reduced to provide a second cylindrical surface |I5 and a second annular shoulder H6. At its discharge end, the oxygen passage is counterbored to provide a short enlarged cylindrical passage section |I'I and a short flaring or frusto-conical passage section ||8, the latter extending from the cylindrical section I |'I to the front end or face I|9 of the body ||0. The acetylene passages |I2 terminate at the shoulder ||6 and open into an 4annular acetylene distributf'- ing chamber |20. The two outer sides ofthe distributing chamber |20 are provided by the skirt |2| and the inturned flange |22 of an end cap |23. The skirt |2| tightly fits the cylindrical surface I|3 and abuts against and is soldered to the shoulder I4. i The iiange |22 bears gas tightly against the end of body I I0, and its inner edge ,|24 is substantially the same diameter as and coaxial with the larger diameter of the frustoconical passage section ||8, and thus provides the sole discharge orice of the nozzle. i

A number of short forwardly inclined passages or ports |25 extend from the surface |I5 to the frusto-conical passage section H8, whereby acetylene is discharged from the distributing chamber |20 into the central passage and obliquely against the oxygen stream flowing therethrough. The row of acetylene jets, thus discharged forwardly yobliquely against the periphery of the outwardly owing oxygen stream, mix with a peripheral layer of said stream to form a sheath of combustible preheating gas encircling the oxygen stream; and the latter, preferably having a greater pressure and velocity than the acetylene jets, exerts an ejector action to draw the acetylene against its surface; and the flow of the gases through the central cylindrical opening in the cap |23 aids further in providing the sheath of combustible gas' around the cutting oxygen stream.

Because of this particular structure the length of the preheat flame at the tip of the nozzle is greatly extended in contrast to the flame of the premixed type of nozzle. The advantages of this extended preheat iiame render post-mixed nozzles especially applicable for hot plate cutting because the tips of the nozzles may be positioned more distant from the hot plate and are thus located in a less destructive environment. During the cutting operation greater stability, that is, ability to maintain the temperature of the plate sufliciently high for continuous cutting at the point where the cutting gas impinges upon the work, also results because the preheat flame extends suiciently deep within the kerf cut in the plate.

In operation, the plate or slab |0 is supported and advanced by the rolls R up to the point where it is to be severed. Carriage C is swung down abgut the rivet 39 t9 e ,heric'eial @retelling P9@ angelo sitidn @ver the slab. and the nozzles N are ne: sitidned tieiisverselr ,by rotatieitef Iieiidwh" e1 5| until they are in' starting positiont The nut 3 9 may be turned by 'a ,usp'anner wrench to tegu: 1ste the length ef the adjustable lirik L td e. height .surment t0 meiriteiifi the dertigste C serif .Zontdl and parallel with the sdrfaee 9i the plete l0. The gate valve `on vthe oxygen manifold is maintained elssed- The eiste valve .2,6 the by-,pass about the gate valve it is adjusted to: gether with the acetylene valve 2 8 to provide the proper preheat name at the nozzles. The' gases issue from the iizzie N, desirebly iris' 'et the nozzle ends, and are ignited, as by the heat of the hot slab. The resulting post-mixed names F preheat a row of spaced areas on the plate Il l. When such areas have been sufficiently pre# heated, Whieii requires Only e very short' time, the mei-n sxveen'valve 2s is @relied t0 PrQVide the Loxygen Ajets J for piercing the slab. The p reheat arns continue burning in crder to pro-v vide sufficient heat at the top of the kerf to assist the thermochemical reaction kof the oxygenjets with the metal.

Depending upon the selected cutting procedure, immediately or when the reaction has progressed sufficiently to completely piercev .the plate Hl, vhandvvheel 5I yis turned to move the jets relative: ly to the plate l0 along a line extending through the centers of the pierced areas as indicated by the arrow A in Figs. 6 and 7, the rate of turning being suiflcient to maintain a rapid Vcutting action to cut through the metal sections between the pierced areas. As the handy/ heel 5| isro'f tated, the threaded rod 50 advances through the 4 8 toward the block 52. VThe movement of the bored block ,43 is transmitted by the bearing 4.6 and arm 45 .to .the adjustable link L to swing or tilt it withrespect to the plate' I0, and hori: zontally move the carriage C at a regulatd cutting speed. As the carriage C, supported on the wheels i9, moves transverselycf the surface of the plate I0, the adjustable link L` slots/ily pivots on the trunnions 35 toward a position in,-

rigdiy heid threaded biocr 1,52 and puiis'tne block dicated by the broken lines of Fig. 7. AAsthe vertical height of the Aadjustable link gradually de,- creases, the .extension i ,of the nut ,.319 slides cut,- vvardlyl in the recess M ofthe -sleeve 3 'l`to main,s tain the vcarriage C in a horizontal position'. At

the end of .the severing operation the carriage i C may be swung upwardlyfaboutthe Vpivot L to lift the entire carriage and the .blot/pipes there,.- on ,away from the severed plate WI retractedposition is shown bythe broken linev .representation of the right handend of carriage Cin Fig, 7. As shown'in Figs. 6 and 7 ,only two valves are .needed when postmiied nozzles are used, .there being .one valve for 'the Voxygen Vand Vone `for ,the .fuel gas, whereas .when premixed nozzles are used at least -tvvovalves vrare usually provided oneach nozzle.

As previously explained, the herein disclosed severing method and ,apparatus V of Figs.- d to v 8 Vare especially useful in successivelyand zrapidly ,severing .elongated relatively thick nretalbodieis, such as steel plates, slabs, etc. tofrop Ac r: c',u t them into ,sections while :they are h oft fand in transit .through mili Drediietieri edtiiemeiit, as be.- tween a rolling ,millfand other `proce: ing 'mean/s, .and in synchronism with the prod ticncycle. It will be understood that anyfsuitable l,fuel ,gas Y other than acetylene may be .utilizedand that oxygen or mixtures containingoxygen may be .utilized for the combustion-supportingandmetal- ,remet/ ingress streamsresveetirelz The pttrtisii- 8 1er embodiments herein described and illustrated. iii feilrilvalw JSS 'are 'Prsiited @indio-ate 149W the'inVeetie-ii inerbeeppiieSi-f Thev reason the post-mixed nozzles are better adapted for -severing thick Work is because, as stated above, the postmixed flame is longer than the pre-mixed ame. In the 'prior patent of Barnes et al. 2,356,196, dated August 22, 1944 iiled March 30, 1940), page 5, column'l, line 32',l the post-mixed'hanne is said to be more nearly unitorn in temperature throughout than isthe prefinixed llame, which is hottestV at the tip oi the inner'cone. "These characteristics enable the post-mixed nozzle to be'helda greater distance `rfrom the Work when cutting than can the pre; mixed nozzle, as mentioned above. If the premixed nozzle Were held as far away from the Work as can the post-mixed nozzle, the pre-fmixed nozzle would be less stable, i. e. in Adanger of losing the cut v vith relative movement ber tween the work and nozzle, unless the rate of such relative movement were greatly reduced. Holding a pre-mixed cutting nozzle close enough to the adjacent surface of a thick body of work has two disadvantages that a post-mixed nozzle does not have. These are the greater danger of of backre with a pre-mixed nozzle and the fact that any preheating'is not the same at a great depth or distance from the nozzle.' With these characteristics in mind, it may now be appreciated in the Iprocess of Fig. 3 that as a postmixed nozzle lN moves'into that portion of the vvork where the effective depth decreases, i. e. in that portion Where the upper surface is the iriclined base of the slots, the eiect is the saine as'if the separation between the workt and nozzle were increased. As a result, there is danger of losing 'the cut, unless a postlmix'ed nozzle is used, or' unless the rate of 'relative' movement of thick work past a pre-mixed nozzle is greatly reduced. With a post-mixdl nozzle', v rapidity of cutting mer be meinteiiiedf What is .tieiiiieii is:

1. A method of rapidly transversely severing an elongated metal body'which is'of substantial width and .ofV substantially rectangular crosssection, such as a steel plate or slab, While such body is supported horizontally," 4suchv method comprising providingfa horizontal rovv .of rectilinearly .movable post-mixedflamev cutting nozzles equally spaced apart; correlating the number of nozzles so provided and the distance they are .spaced apart with the vvidth `dil n en"s if ;f1. Jf such bedr and thetime interval available ,iii apro,- diietisii eyele for completely trarisv'erseiysever- .ing the body by a ,single advance or stroke of said row ,of vnozzles transversely of said body; positioningsaid row of nozzles so that thecutting flame' orifices of vthe .nozzles'are opposite and 'generally parallel to a horizontal cutting' lineo'n the upper horizontal surface of a body to be cut and also so that rthe naine of the leading nozzle of'sufch'row of nozzles 'is directed at an area on said Acutting line that is axially spaced from a 'readies' latertiedeetf seid bedr @distante eletti "to the axial distance said nozzles are spaced apart; applying `pre1treating ilarnfes 4from' said nozzles above said 'surface .to spaced'areason said `surface kalong said cuttingline; vapplying cutting oxygen jets from such rnozzles'against suchl preheated 'areas to begin piercing said body, cutting al plurality of alined and separate kerfs through said body `duringthe piercing operation; upon 'completion of piercing throughsaid body, movine said row ef nozzles vand.the.1erehetting deines and cutting j ets thereof only a single stroke substantially equal to the distance adjacent nozzles are spaced apart and horizontally and transversely of said body solely toward its leading lateral edge, until the cutting jet from the orince of said leading nozzle cuts a kerf extending through said lateral edge and until such alined kerfs entirely through the body merge end to end; and then shutting off said preheatlng flames and said oxygen cutting jets.

2. A method of cutting a metal body of thick hot steel, which comprises simultaneously directing aligned and spaced ignited jets of post-mixed fuel gas and oxidizing gas against spaced areas of said body; upon attaining the kindling temperature of said body, substantially simultaneously increasing the ilow of oxidizing gas in said post-mixed jets in excess of the amount required to support combustion of said fuel gas; thereby reacting with said body an excess oxidizing gas issuing from said jets; and thereupon before any of said jets have pierced said body relatively moving said jets and said body in a single pass in the direction of a line extending through the centers of said areas and for a distance suflicient to react with the metal sections between said areas and entirely sever said body.

3. A method of piercing and cutting a Wide, thick, hot body of metal comprising substantially uniformly spacing a plurality of post-mixed preheat flames in alignment across said body when the same is below the ignition temperature of the metal and oxygen, flowing cutting oxygen to said llames while electing relative movement between said body and said plurality of llames in only one direction of the flame alignment during both piercing and cutting of said body, continuing said relative movement after said body has been pierced and until the body has been severed, and then shutting olf the preheat flames and cutting oxygen.

JAMES H. BUCKNAM. ROGER S. BABCOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 703,940 Menne July 1, 1902 1,084,692 Bucknam Jan. 20, 1914 1,136,490 Smith Apr. 20, 1915 1,311,815 Harris July 29, 1919 1,345,242 Reynolds June 29, 1920 1,352,381 Reynolds Sept. 7, 1920 1,519,582 Harris Dec. 16, 1924 1,554,408 Coberly Sept. 22, 1925 1,698,173 Royer Jan. 8, 1929 1,709,886 Smith Apr. 23, 1929 1,879,346 Lawrence Sept. 27, 1932 2,175,160 Zobel Oct. 3, 1939 2,195,384 Zobel Mar. 26, 1940 2,221,788 Doyle 1 Nov. 19, 1940 2,345,412 Moore Mar. 28, 1944 2,417,412 Herbst Mar. 18, 1947 2,425,709 Bucknam et al Aug. 19, 1947 FOREIGN PATENTS Number Country Date 701,786 France Mar. 23, 1931 OTHER REFERENCES The Oxy-Acetylene Handbook, copyright 1943, pages 458 and 460. 

1. A METHOD OF RAPIDLY TRANSVERSELY SEVERING AN ELONGATED METAL BODY WHICH IS OF SUBSTANTIAL WIDTH AND OF SUBSTANTIALLY RECTANGULAR CROSSSECTION, SUCH AS A STEEL PLATE OR SLAB, WHILE SUCH BODY IS SUPPORTED HORIZONTALLY, SUCH METHOD COMPRISING PROVIDING A HORIZONTAL ROW OF RECTILINEARLY MOVABLE POST-MIXED FLAME CUTTING NOZZLES EQUALLY SPACED APART; CORRELATING THE NUMBER OF NOZZLES SO PROVIDED AND THE DISTANCE THEY ARE SPACED APART WITH THE WIDTH DIMENSION OF SUCH BODY AND THE TIME INTERVAL AVAILABLE IN A PRODUCTION CYCLE FOR COMPLETELY TRANSVERSELY SEVERING THE BODY BY A SINGLE ADVANCE OR STROKE OF SAID ROW OF NOZZLES TRANSVERSELY OF SAID BODY; POSITIONING SAID ROW OF NOZZLES SO THAT THE CUTTING FLAME ORIFICES OF THE NOZZLES ARE OPPOSITE AND GENERALLY PARALLEL TO A HORIZONTAL CUTTING LINE ON THE UPPER HORIZONTAL SURFACE OF A BODY TO BE CUT AND ALSO SO THAT THE FLAME OF THE LEADING NOZZLE OF SUCH ROW OF NOZZLES IS DIRECTED AT AN AREA ON SAID CUTTING LINE THAT IS AXIALLY SPACED FROM A LEADING LATERAL EDGE OF SAID BODY A DISTANCE EQUAL 